U RINARY tract infections (UTIs) are common problems in both inpatient and outpatient settings. Despite the frequency with which these infections are encountered and the volume of literature concerning them, controversy still exists about their optimal treatment. Recent studies have helped to delineate the etiologies of acute dysuria in women, one of the most common presentations of UTIs, and have begun to compare different regimens of treatment. It is now apparent that Stuphylococcus saprophyticus is a common cause of UTIs in young women. Nosocomial UTIs remain a major cause of morbidity and mortality despite vigorous attempts to prevent them. New antimicrobial agents are available for treatment of UTIs; some may eventually replace nephrotoxic aminoglycosides for treatment of severe or complicated infections. Diagnostic tests and antimicrobits are not inexpensive; in these days of cost containment, the clinician is challenged by the need to find the most cost-effective means to treat and prevent UTIs. The goals of treatment of UTIs are to provide relief of symptoms, eradicate the focus of infection, prevent recurrences due to either relapse of the same infection or acquisition of a new infection, and to prevent renal damage. Unless obstruction of urine flow caused by anatomic variant, stone, or other problem is present, UT1 in adults rarely causes renal parenchymal damage sufficient to lead to end-stage renal disease. Success in treatment of UT1 correlates best with the susceptibility of the causative microorganism to concentrations of antimicrobics, which can be attained in urine rather than the concentration attainable in blood. In theory, use of bacteriocidal drugs would be preferable, but there is no real evidence that bacteriocidal drugs are superior to bacteriostatic agents. Because response to therapy is dependent on a number of factors including the site of infection, presence of complicating factors such as neurogenie bladder, stones, or need for indwelling catheters, there is no single best treatment plan. Rather, the costs, side effects, inconvenience to the patient, and the likelihood that a particular treatment will be effective must be evaluated for each patient. This article discusses some of the recent developments in the understanding and therapy of the major categories of UTIs that occur in adults: acute dysuria of women, pyelonephritis, prostatitis, and asymptomatic bacteriuria in special situations. For more comprehensive reviews of UTIs, the reader is referred to several recent publications.’ 4